Phosphonium ethyl amine derivatives



States dice 3,320,321 PHOSEHONHUM ETHYL AMENE DERIVATIVES Martin Grayson, N orwallr, Patricia Tarpey Keough, Ridgeiield, and Michael McKay Rauhut, Norwallr, Cnn., assignors to American Cyanamid Company, Stamford, Conn, a corporation of Maine No Drawing. Filed June 28, 1963, Ser. No. 291,281 Claims. (Cl. 260-583) The present invention relates to organophosphorus compounds and to a method of preparing same. More particularly, the instant discovery concerns phosphonium salt derivatives of tertiary phophines.

It has been found that tertiary phosphines generally will react with halo-substituted ethanol to produce the corresponding trialkyl-, tricycloalkyl-, or tri-aryl- Z-hydroxyethylphosphonium salts. In turn, these salts may be acylated using a lower alkanoic anhydride, lower alkanoic acid, or the like, to produce their corresponding trialkyl-, tricycloalkyl, or triaryl- Z-acetoxyethylphosphonium salts.

The following equations illustrate this general reaction:

R R R each representing, as will be seen hereinafter,

alkyl, cycloalkyl and aryl,

X representing halogen or tetraphenyl borate, and Y representing the residue of an acylating or esterifying agent. The following is a typical embodiment of generic Equations A and B, above;

9 9 (ll-CliHshP BI'CHzCH2OH (n-C-rHQsPCI-IaCHzOH-Br base The trialkyl-, tricycloalkyl-, and triaryl- Z-acetoxyethylphosphonium salts prepared as above may, in turn, be converted to their corresponding vinylphosphonium salts according to the following general equation:

in which R R R Y and X are the same as above.

The following is a typical embodiment of Equation C, above:

More specifically, in generic Equations A, B and C, above R R and R each represent alkyl C C substituted alkyl C C cycloalkyl, and aryl; X represents halogen, such as bromo, chloro and iodo, and tetraphenyl borate; and Y in Equations B and C represents the residue of an acylating agent as shown in the specific embodiments, supra.

Typical tertiary phosphine reactants are the following: trimethylphosphine, triethylphosphine, tripropylphosphine, tributylph-osphine, tripentylphonsphine, trihexylphos hine, triheptylphosphine, trioctlyphosphine, trinonylphosphine, tridecylphosphine, triundecylphosphine, tridodecylphosphine, tritridecylphosphine, tritetradecylphosphine, tripentdaecylphosphine, trihexadecylphosphine, dodecyldiethylphosphine, dioctylpropylph-osphine, diethylbutylphosphine, butlyethylhexylphosphine, tri(2 methoxypentyl)phosphine, tris-2 cyanoethylphosphine, diethyl- 2 ethoxyheptylphosphine, tricyclopropylphosphine, tricyclohexylphosphine, triphenylphosphine, diphenylnaphthylphosphine, trixylylphosphine, tritolylphosphine, tris- (para-ethoxyphenyl)phosphine, tris(para chlorophenyl) phosphine, tris(2-chlorophenyl)phosphine, tris(3-bromophenyl)phosphine, and the like.

Typical esterifying agents follow: lower alkanoic anhydrides, such as acetic anhydride, propionic anhydride, butanoic anhydride; lower alkanoic acids, such as formic acid, acetic acid, propionic acid, butanoic acid; acylating (C -C alkanoyl) halides, such as acetyl chloride, propionyl bromide, butyryl iodide, octanoyl chloride, dodecanoyl bromide, stearyl chloride, hexanoyl bromide; isopropenyl acetate; aryl sulfonyl halides, such as paratoluenesulfonyl chloride, phenyl sulfonyl bromide, 2,4- dimethylphenylsulfonyl chloride; alkyl (lower) chloroformates, such as ethylchloroformate, butylchloroformate; alkyl (lower) carbonates, such as diethylcarbonate, dipropylcarbonate, dibutylcarbonate; ketene; dimethyl sulfate; nitrosyl chloride; and trimethyl phosphate.

In Equation C, above, typical suitable inorganic and organic bases are: alkali metal hydroxides, such as sodium hydroxide, potassium hydroxide, lithium hydroxide; alkali metal carbonates, such as sodium carbonate, potassium carbonate, lithium caronate; alkaline earth metal hydroxides, such as magnesium hyroxide, barium hydroxide, calcium hydroxide; alkaline earth metal carbonates, such as magnesium carbonate, barium carbonate, calcium carbonate; activated alumina; and quaternary ammonium hydroxides, such as tetraalkyl (lower)ammonium hydroxides, including tetramethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabenzylammonium hydroxide; and basic ion exchange resins.

The reaction in Equation A hereinabove is carried out at a temperature in the range of 30 C. to 250 C., preferably 60 C. to 180 C. The Equation B reaction, above, is best carried out at a temperature in the range of 5 C to C. As to Equation C, above, this reaction is generally carried out at a temperature in the range of 20 C. to C., preferably 50 C. to 150 C.

Each of these three reactions may be carried out at atmospheric, sub-atmospheric or super-atmospheric pressure; preferably, however, reaction is carried out at atmospheric pressure. By the same token, the ratio of the reactants in each of Equations A, B and C is not critical, an excess of either reactant, in each equation, with respect to the other being suitable. In Equation B, however, an excess of about 10% by weight of the acylating agent relative to the phosphonium salt reactant is preferred. Generally in Equations A and C stiochiometric amounts of the reactants are employed.

The reactions of Equation A, above, are best carried out in the presence of an inert organic solvent, i.e., a solvent which does not enter into or otherwise interfere with the reaction under the conditions contemplated herein. Typical solvents are dimethoxyethane, dioxane, ethylacetate, tetrahydrofuran, and the like.

The reactions of Equation B similarly are best carried out in the presence of an inert organic solvent of the type described for Equation A, as well as acetic acid, dimethylformamide, diglyrne, and the like.

As to Equation C, typical suitable inert organic solvents in which the phosphonium salt is solvent, which solvents do not interfere or enter into reaction to any substantial degree, are dimethoXy-ethane, dioxane, dimethylforamide, diglyme, acetonitrile, ethylacetate, tetrahydrofuran, and other like linear and cyclic ethers, acetate esters (lower alkyl).

Alternatively, it has been found pursuant to the instant 1 Typical are: polymeric quarternary aniomniuni salts, e.g., polymeric trimethylbenzyl ammonium chloride, etc,

discovery that the products of Equation A, above, may be converted directly to the products of Equation C, thusly,

in the presence of any base given above for Equation C and at a temperature in the range of 100 C. to 250 C. As in Equation C, a solvent of the type given hereinabove for Equation C is suitable and herein contemplated. If desired, the reaction may be carried out in the presence of a dehydrating agent, such as a siliceous agent including silica (e.g. silica gel), silica-alumina, and the like, in which other inert organic solvents are also suitable, e.g. aromatic hydrocarbons, such as toluene, benzene, xylene, cymene, and the like, methylene chloride, ethylene chloride, etc.

The products of Equations A, B, C and D above are useful as fire retardants in plastics, e.g., from 0.5 to 30 parts by Weight of any one of above compounds when incorporated into 100 parts by weight of a thermoplastic polymer material, such as polyethylene, polypropylene, polystyrene, polyacrylate, polymethylmethacrylate, or the like, provides enhanced fire retardance to the polymer material upon exposure to an open flame.

While the following examples specify certain details as to certain embodiments of the present invention, it is not intended that these details impose unnecessary limitations upon the scope of the instant discovery, excepting of course that these limitations appear in the appended claims:

EXAMPLE I T ributyl-Z-hydroxyethylphosphonium tetraphenylborate T ributyl-2-hydroxyethylphosphonium bromide, obtained from combining tributylphosphine and 2-bromoethanol in 1,2-dimethoxyethane and refluxing under nitrogen, is dissolved in water and treated with excess 0.1 N sodium tetraphenylboron. The resulting precipitate is filtered and recrystallized from ethanol to yield product tributyl-2-hydroxyethylphosphonium tetraphenylborate with melting point 124 C.125 C.

Analysis of prduct.Found: C, 80.03; H, 9.00; P, 5.35. C I-I O requires: C, 80.55; H, 9.25; P, 5.47%.

As is evident from this example, the halide salts of Equation A may be converted, in situ or after recovery thereof, to the corresponding tetraphenylborate salts.

EXAMPLE II T ribatyl-2-acet0xyethylph0sphonium bromide 1,2-dimethoxyethane (275 milliliters), freshly distilled from calcium hydride, 2-bromoethanol (133 grams, 1.06 moles), and tributylphosphine (204 grams, 1.01 moles) are combined under nitrogen and refluxed at 85 C. overnight with stirring. A heavy oil forms within an hour. Isopropenyl acetate (320 grams, 3.2 moles) and 48% I-IBr (3 drops) are slowly added to the reaction mixture which is then refluxed 18 hours. Volatile components are removed in vacuo at 70 C. Product (372.5 grams; 99.9% yield) remains as a thick hygroscopic oil, which could be forced to crystallize by stirring in a benzenepetroleum ether (boiling point 30 C.60 C.) mixture. Crystalline tributyl-2-acetoxyethylphosphonium salt is obtained from part of the oily product by freeze drying a benzene solution of the oil.

EXAMPLE III Tribatyl-Z-aceioxyethylphosphonium tetraphenylborate Tributyl-2-acetoxyethylphosphonium bromide oil (16.2 grams produced as in Example 11, above) is dissolved in water and treated with sodium tetraphenylboron (15 grams) dissolved in water. A white precipitate appears which is filtered and recrystallized from ethanol containing enough acetonitrile to cause solution at the boiling point of the mixture. Tributyl-Z-acetoxyethylphosphoniunr tetraphenylborate (16.7 grams) is obtained with melting point of 177 C.l79 C.

Analysis of pr0dact.--Found: C, 76.65; H, 8.83; P- 5.24. C ,,H O BP requires: C, 78.93; H, 8.94; P, 5.10%.v

EXAMPLE IV Triphenyl-Z-acetoxyethylphosphonimn iodide 2-iodoethyl acetate is prepared from the nucleophilic exchange reaction of sodium iodide and 2-chloroethylacetate in refluxing acetone under nitrogen (boiling point 86 C.-90 C. at 33 milliliters mercury). Triphenylphosphine (7.35 grams) is reacted with 2-iodoethylacetate (24 grams) under nitrogen with stirring at C. for 4.5 hours. The excess 2-iodoethylacetate is distilled off in vacuo. Crude, brown crystalline product (14.20 grams) is obtained by washing oily residue with ether. It is washed with ether, ethylacetate, and acetone and recrystallized from acetonitrile to give product (7.90 grams) with melting point 161 C.163 C.

Analysis 07 pr0dact.-Found: C, 55.16; H, 4.80; I, 26.77; P, 6.45. C H O IP requires: C, 55.47; H, 4.66; I, 26.66; P, 6.51%.

Example IV represents still another embodiment of the present invention wherein the product salts of Equation B, above, are prepared directly from the reaction of a 2-haloetl1yl acetate with a tertiary phosphine of the type contemplated herein.

The process of Example IV, above, may be carried out using any of the tertiary phosphine reactants contemplated herein and the corresponding tri-substituted 2-acetoxyethylphosphonium halide produced and recovered, according to the following equation l e 9 runner X01120H200-0H3 R R R PCHzCHzOY'X ethyl acetate and 2-chloroethyl acetate.

Tables A, B, C, D and E, which follow, correspond to Equations A, B, C, D and B, respectively. The examples in Tables A and B are carried out essentially as in Examples I and II, respectively supra, excepting of course as shown in Tables A and B. The examples in Table C are carried out essentially as in Example LX, infra, excepting of course as shown in Table C. Like- Wise, the products of Table D are recovered essentially as in Example LX, infra. The examples in Table E are carried out essentially as in Example IV,- supra, except ing of course as shown in Table E.

TABLE BConti11ued Product of Moles, Example Example A Moles, Solvent Milliliters Temp., Product No. No. QB 9 A (1111.) 0.

R31 OH CHZOH'X XXV VIII 0. 9 Nitrosyl Chloride 1.1 Diglyme 120 2-nitroethyltributy1 phcsphonium iodide.

XXVI IX 1. Acetyl Chloride 1. 2 DME, 500 m1 30 2-acet0xyethyltriisobutylphosphom'um chloride.

XXVII XI 1. 0 p-Toluenesulfonyl Chloride... 1. 0 DME, 200 ml 60 2-(p-toluenesulfonylqxy) ethyltridodecylphosphonium chloride XXVIII--... XIII 1. 0 Trimethyl Phosphate 1.1 Acetic Acid, 500 ml.. 80 2dimethylphcsphatoethyltriethyl phosphonium chloride.

XXIX XII 1.0 Proplonic Acid 2.4 DMF, 300 ml 2-propionyloxyethyltrihexadecylphos phonium chloride.

XXX: XIV 1T0 Butanoic Anhydride 1. 0 DMF, 1,000 ml .1 2-butyryloxyethylbutyl.

ethylhexylphosphonium chloride.

XXXI XV 0.8 Acetic Acid 4. 0 None 118 2-acetoxyethyldiethyl- 2-ethoxyethylphosphonium chloride.

XXXII XVI 0.9 Acetyl Chloride 1. O DME, 200 ml 65 2-acetoxyethyltricyclohexylphosphonium bromide.

XXXIII...- XVII. 1. 0 Hexanoyl Chloride 1. 9 Dioxane, 150 ml-.... 25 2-hexanoy1oxyethyltricyclopentylphosphonium chloride.

XXXIV XIX 1.0 Acetic Anhydride 6.0 None 100 2-acetoxyethy1tri heny1 phosphonium iodide.

XXXV XVIII. 1.1 Stearyl Chloride 3. 3 DME, 700 ml 2-stearyloxyethy1diphenylnaphthylphosphonium iodide.

XXXVI.- XX 1. 0 Dodecanoyl Bromide 4. O DMF, 1,000 ml 40 2-dodecanoyloxyethyltri-(parachlorophenyl) phosphonium chloride.

XXXVII. XXI 1. O Phenylsulfonyl Bromide. 1. 0 Dioxane, 600 ml... 2-(phenylsulionyloxy)- ethyltri(para-tolyl) phosphonium chloride.

XXXVIII. V 1. 0 Ethylchloroformate 2. 0 Diglyme, 300 ml. 40 2-(ethoxycarbonyloxy)- ethyltrimethyl phosphonium bromide.

XXXIX VII 0.9 Dipropyl Oarbonate..-. 3.0 DME, 250 ml 100 2-(propoxycarbonyloxy) ethyltributylphosphonium chloride.

XL VII 1. 0 Ketene 1. 0 THF, 500 ml Z-acetoxyethyltributyl phosphonium chloride.

1 DMF =Dimethylformamide.

TABLE 0 6B 9 Base EB 9 R R R P CHzCHzOYX R R R P CH OH 'X 63 Example Product of RIRZR Base Moles of Solvent 1 Milliliters Temp., Product N 0. Example N o. 9 Base (1111.) C.

CHzOY'X XLI XXII 1. 0 KzCOg 1. 0 DME, 300 m1 33 Vigyltri rdnethylphosphonium romi e. LII XXIII 1. 0 NmCOa 2.0 Dioxaue 300 ml 100 vinfiltrillmtylphosphonium on e. 111 XXIV 1. 0 LlzCOa 4. 0 Ethyl acetate, 500 ml-. Do. XLIV XXV 2.0 Mg(CO;) 8.0 Diglyme Vipgllgibutylphosphonium XLV XXVI 0.5 Ba(OI-I)z 1. 0 Acetonitrile, 500 1111.... 80 Vinyltriisobutylphosphonium chloride.

XLVI XXVII 0.9 Ca(OH)2 1. 1 THF, 600 ml 60 Vinyltridodecylphosphonium chloride.

XLVII...-- XXVIII---. 1. 0 Polymeric trimcthylbenzyl 4. 0 DME, 400 ml 85 Vinyltriethylphosphonium amlnoniurn chloride. chloride.

XLVIII XXIX 1. 0 KOH 1. 0 THF Vinyltrihexadecylphosphonium chloride.

XLIX XXX 1.0 NaOH 1.0 Acetonitrile 20 Vinylbutylethylhexylphosphonium chloride.

L XXXI 1. 0 LiOH 1. 0 -....do 60 Vinyldicthyl-Z-ethoxyethylphosphonium chloride.

LI XXXII. 1. 0 Mg(OH)2 3.0 THF 72 Vinyltricyclohexyl phosphonium bromide.

LII XXXIIL... 2.0 0&(003) 1. 0 DiOXane Vinyltricyclopentylphosphonium chloride.

LIII XXXIV- 0. 5 Ba(C0a) 1. 0 DME 81 Virlgligiphcnylphosphonium L V XXXV 3. 0 Polymeric triethylloenzyl 1. 0 Dioxane 97 vinylphenylnaphthylphosammonium hydroxide. phomum iodide.

LV XXXVI 1. 0 d0 5.0 DME 50 Vinyltri(para-chlorophenyl) phosphonium chloride.

LVI XXXVII 1. 0 Activated alumina. 1. 0 THF 35 Vinyltri(para-tolyl)phosphonium chloride.

LV I XXXV1II. 1. 0 Tetramethylammonium 1. 7 Diglyme 42 Vinyltrimethylphosphonium hydroxide. bromide.

VIII XXXIX.... 2.0 Tetrapropylammonium 1. 0 DMF 37 Vinyltr utylphosphonium hydroxide. chloride.

LIX XL 1. 0 Tetrabenzylammonium 1. 0 DME 25 D hydroxide.

1 When not specified the amount of solvent employed is 500 milliliters.

TABLE D 65 9 base 99 9 R R R PCH2CHZOH'X R R R PCH=CHrX Example Product of Temp, Dehydrating 500 N 0. Example Base C. Agent Milliliters Product N o. of Solvent 120 Silica gel 1 DME Vinyltributylpliosphouium chloride. 100 Silica-alumina DME Vinyltridodecylphosphoniuin chloride. 220 THF Vinyltrihexadeeylphosphoniurn chloride. 180 Silica-alumina Dioxane. Vinyldiethyl-2-etlioxyethylphosplionium chloride. 150 Silica gel 1 DM Vinyltricyelohexylphos honium bromide. Vinyldiphenylnaphtliy phosphonium iodide.

Vinyltripheuylpliosphonium iodide. NazCOa Vinyltri(para-chlorophenyl)phosphonium chloride. Activated alumina. Vinyltri(para-tolyl)phosphonium chloride.

1 Finely-divided particulates.

TABLE E Example Temp, 1

N 0. R R R P II C. Solvent Product XCHzCHzO C-OH:

firiclodecylphospliine X=Br Ethanol Tridocdcyl-2-aeetoxyethylphosphonium bromide. Tricyclehexylphospliine X=I 85 Acetonitrile- TrieyclohexylQ-aeetoxyethylphosphouium iodide.

Tris (2-ch1oropl1enyl)-phosphine. X Cl Acetone.-. Tris(2-cl1lorophenyl) 2-acetoxyethylphospliouiuin e on e. 13 Tris(2-1'11ethoxypentyl)-pl1os1.)hirle.| X=I 50 Dioxane. 2-acetoxyetliylpliosphonium iodide.

l Reflux.

By finely-divided particulates in Table D is intended 28 to 200 mesh. Larger or smaller particulates are like wise within the purview of the instant discovery.

EXAMPLE LX Tribulylvinylphosphonium bromide Tributyl 2 acetoxyethylphosphonium bromide (23.7 millirnoles) is dissolved in 1,2-dirnethoxyethane milliliters) and sodium carbonate (5.0 grams, 47 millimoles) is added. The mixture is stirred at reflux under nitrogen for 8 hours. The solid is filtered off and washed with hot 1,2-dimethoxyethane. The combined filtrates are evaporated to leave as semi-solid residue. Recrystallization from ethyl acetate yields product tributylvinylphosphonium bromide (3.3 grams, 10.7 millimoles, 45% yield with melting point 148 C.150 C.). Further recrystallization from ethyl acetate-acetonitrile raises the melting point to 151.5 C. to 152.5 C.

The products of equations and Tables B, C, D and E hereinabove may be reacted, pursuant to the present invention and according to the reaction conditions of Equation C, supra, with: ammonia; a primary aliphatic or cycloaliphatic amine (C C substituted or unsubstituted; a secondary aliphatic or cycloaliphatic amine (C C substituted or unsubstituted; diamine (H N-R-NH wherein R is lower :alkylene or phenylene); morpholine; piperidine; pyrrolidine; pyrrole; piperazine; imidazole; lower alkyl-substituted imidazole; benzimidazole; and the like. The product salt has the formula (R R R P CH CH ),,A]X,,

wherein R R R and X have the meanings given herein- EXAMPLE LXI T ibutyl-Z-(diellzylamino)ethyl phosphom'um bromide Tributylvinylphosphonium bromide (154.4 grams, 0.05 mole) is mixed with milliliters of diethylamine with stirring and there is an exotherm to C.- C. When the exotherm subsides, the diethylamine is removed in vacuo, and the clear residual syrup represents a quantitative yield of tributyl-Z-(diethylamino)ethyl phosphonium bromide. Treatment of this syrup with a 1 normal aqueous solution of soidum tetraphenyl boron yields a crystalline derivative, melting point C.- 156 C.

AnaIysis.Calculated for C H PNB: C, 81.90; H, 9.98; P, 5.03; N, 2.27. Found: C, 81.35; H, 9.59; P, 5.05; N, 2.21.

EXAMPLE LXII EXAMPLE LXIII Triburyl-Z(2'-benzimidazole) ethyl phosphonium bromide Tributylvinylphosphonium bromide (15.4 grams, 0.05 mole) is allowed to react with 5.9 grams (0.05 mole) of benzimidazole in 50 milliliters of dimethoxyethane as in Example II. The product is obtained as a gummy syrup which may be converted to the crystalline tetraphenyl borate derivative, melting point 155 C.

Analysis.-Calculated for C H PN B: C, 81.77; H, 8.54; P, 4.68; N, 4.23. Found: C, 81.14; H, 8.41; P, 4.34; N, 4.53.

TABLE F-Continued Product of Moles Moles Temp., Example No. Exlarmple of (1) A of A Base Solvent; 0. Products LXXVI LIV- 2.0 Pyrrolidine 1.0 DME 28 PCB:

k/ 2 a V 69 CH-N 9 LXXVII XXXVII- 1.0 Plpel'ldlne 3.0 22 Ii LXXVIII XXXIV- 2.0 Piperazine- 1.0 THF 75 CHzCHa N N CH2CH2P The products of Examples LXI through LXXVIII may be employed as fire retardants in the manner defined hereinabove for the phosphoniurn salts of Equations B through E.

In Table F 500 milliliters of solvent is used in each example. As is also evident from Table F, an additional base is not required, the amine reactant itself being basic. Furthermore, when more than one NH bond is present, such as in ammonia, ethylamine, aniline, ethylene diamine or phenylene diamine, then one or two phosphonium salt reactant moieties may combine with the amine reactant depending on the ratio of salt to amine. Two or more moles of salt per mole of said amine yields a disubstituted amine as in Examples LXIV, LXV and LXXI. If desired, also, the amine reactant, when a liquid, may be used in excess as the solvent. Cf. Examples LXV and LXXVIII.

Clearly, the instant discovery encompasses numerous modifications within the skill of the art. Consequently, while the present invention has been described in detail with respect to specific embodiments thereof, it is not intended that these details be construed as limitations upon the scope of the invention, except insofar as they appear in the appended claims.

We claim:

1. A compound of the formula alkyl C C1s, cycloloweralkyl, phenyl, naphthyl and substituted phenyl, wherein the substitut'ents for alkyl are [USO-04111931CHzGHzN(CHs) 01 01 References Cited by the Examiner UNITED STATES PATENTS 3,005,013 10/1961 Grayson et a1. 260583 FOREIGN PATENTS 926,998 5/1963 Great Britain.

OTHER REFERENCES Wittig et al., Justus Liebigs Annalen der 619, 1958, pp. 10-11.

ALEX MAZEL, Primary Examiner. RICHARD J. GALLAGHER, Assistant Examiner.

Chemie, vol. 

1. A COMPOUND OF THE FORMULA 